<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 300px;
            height: 200px;
            /* 边框粗细 */
            border-width: 5px;
            /* 边框样式 */
            /* 实线 */
            border-style: solid;
            /* 虚线 */
            border-style: dashed;
            /* 点线 */
            border-style: dotted;
            /* 边框颜色 */
            border-color: pink;
        }
        /* 边框复合型写法 */
        div{
            border: 1px solid red;
        }
        /* 边框分开写法 */
        div{
            /* 上边框 */
            border-top:1px solid red;
            /* 下边框 */
            border-bottom:1px solid green;
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>